A cerebral aneurysm refers to an aneurysm as a result of swelling of a part of a blood vessel and develops without symptoms until it ruptures and presents as a subarachnoid hemorrhage in many cases. A target of surgical treatments had been a ruptured cerebral aneurysm until recently which caused subarachnoid hemorrhage or a giant cerebral aneurysm which became gigantic and began to oppress a brain around it. However, subarachnoid hemorrhage often results in a so-called sudden death which causes death before a patient is admitted in a hospital and treated or a serious case and almost 50% of them have a bad outcome even in a current time of advanced medical techniques. Thus, early detection of unruptured cerebral aneurysm is an extremely important problem.
A cerebral aneurysm is detected in an early stage on the basis of three-dimensional images based on volume data including cerebral blood vessels obtained in an initial examination, but it may be diagnosed to have a small risk of rupture in some cases since a size of the cerebral aneurysm is small or the like. In that case, regular follow-up examinations are conducted by using CTA (computed tomography angiography), MRA (magnetic resonance angiography) and the like after the initial examination.
A medical image processing apparatus detects a cerebral aneurysm on the basis of volume data (three-dimensional data set) obtained in the initial examination and the follow-up examinations, makes measurements in accordance with measurement items (a neck area, a volume and the like of the cerebral aneurysm) of the cerebral aneurysm and displays its measurement result. A checker can observe a temporal change of the cerebral aneurysm on the basis of the display. In this case, an operator specifies positional parameters (spatial positions of an identification point of the cerebral aneurysm and a neck surface) for obtaining the measurement result by manually or semiautomatically (click operation) on the three-dimensional image based on the volume data including a cerebral blood vessel.
A detection supporting device and a detection method for detecting a candidate of a cerebral aneurysm from the volume data are disclosed.
According to a prior-art technique, in order to obtain a measurement result relating to a cerebral aneurysm at each follow-up examination, the operator needs to specify the positional parameters again manually or semiautomatically (click operation) on the three-dimensional image based on the volume data including the cerebral blood vessel at each follow-up examination. This specification operation is a burden on the operator, and there is a problem that variation is caused depending on a skill of the operator.
Thus, such a method can be considered for acquiring a measurement result in the follow-up examination by using the positional parameters specified in the initial examination by performing alignment of the volume data obtained in the follow-up examination with the volume data obtained in the initial examination. However, since a shape of the cerebral aneurysm changes by a growth thereof over time, simple alignment of the volume data cannot achieve appropriate alignment.